boost/libs/hana/doc/html/structboost_1_1hana_1_1tuple.html
2021-10-05 21:37:46 +02:00

552 lines
51 KiB
HTML

<!--
Copyright Louis Dionne 2013-2017
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
-->
<!-- boost-no-inspect -->
<!-- HTML header for doxygen 1.8.9.1-->
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.20"/>
<title>Boost.Hana: boost::hana::tuple&lt; Xn &gt; Struct Template Reference</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtreedata.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/searchdata.js"></script>
<script type="text/javascript" src="search/search.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
$(document).ready(function() { init_search(); });
/* @license-end */
</script>
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
extensions: ["tex2jax.js"],
jax: ["input/TeX","output/HTML-CSS"],
});
// Copyright Louis Dionne 2013-2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
MathJax.Hub.Config({
"HTML-CSS": {
linebreaks: {
automatic: true,
width: "75% container"
}
}
});
</script>
<script type="text/javascript" async="async" src="https://cdn.mathjax.org/mathjax/latest/MathJax.js"></script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
<!-- Additional javascript for drawing charts. -->
<script type="text/javascript" src="highcharts.js"></script>
<script type="text/javascript" src="highcharts-data.js"></script>
<script type="text/javascript" src="highcharts-exporting.js"></script>
<script type="text/javascript" src="chart.js"></script>
<script type="text/javascript" src="hana.js"></script>
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectlogo"><img alt="Logo" src="Boost.png"/></td>
<td style="padding-left: 0.5em;">
<div id="projectname">Boost.Hana
&#160;<span id="projectnumber">1.7.0</span>
</div>
<div id="projectbrief">Your standard library for metaprogramming</div>
</td>
<td> <div id="MSearchBox" class="MSearchBoxInactive">
<span class="left">
<img id="MSearchSelect" src="search/mag_sel.svg"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
alt=""/>
<input type="text" id="MSearchField" value="Search" accesskey="S"
onfocus="searchBox.OnSearchFieldFocus(true)"
onblur="searchBox.OnSearchFieldFocus(false)"
onkeyup="searchBox.OnSearchFieldChange(event)"/>
</span><span class="right">
<a id="MSearchClose" href="javascript:searchBox.CloseResultsWindow()"><img id="MSearchCloseImg" border="0" src="search/close.svg" alt=""/></a>
</span>
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.20 -->
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
var searchBox = new SearchBox("searchBox", "search",false,'Search');
/* @license-end */
</script>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&amp;dn=gpl-2.0.txt GPL-v2 */
$(document).ready(function(){initNavTree('structboost_1_1hana_1_1tuple.html',''); initResizable(); });
/* @license-end */
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
onmouseover="return searchBox.OnSearchSelectShow()"
onmouseout="return searchBox.OnSearchSelectHide()"
onkeydown="return searchBox.OnSearchSelectKey(event)">
</div>
<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<iframe src="javascript:void(0)" frameborder="0"
name="MSearchResults" id="MSearchResults">
</iframe>
</div>
<div class="header">
<div class="summary">
<a href="#related">Synopsis of associated functions</a> &#124;
<a href="#friends">Friends</a> &#124;
<a href="#pub-methods">Public Member Functions</a> &#124;
<a href="structboost_1_1hana_1_1tuple-members.html">List of all members</a> </div>
<div class="headertitle">
<div class="title">boost::hana::tuple&lt; Xn &gt; Struct Template Reference<div class="ingroups"><a class="el" href="group__group-datatypes.html">Data types</a></div></div> </div>
</div><!--header-->
<div class="contents">
<a name="details" id="details"></a><h2 class="groupheader">Description</h2>
<div class="textblock"><h3>template&lt;typename ... Xn&gt;<br />
struct boost::hana::tuple&lt; Xn &gt;</h3>
<p>General purpose index-based heterogeneous sequence with a fixed length. </p>
<p>The tuple is the bread and butter for static metaprogramming. Conceptually, it is like a <code><a class="el" href="structstd_1_1tuple.html" title="Adapter for std::tuples.">std::tuple</a></code>; it is a container able of holding objects of different types and whose size is fixed at compile-time. However, Hana's tuple provides much more functionality than its <code>std</code> counterpart, and it is also much more efficient than all standard library implementations tested so far.</p>
<p>Tuples are index-based sequences. If you need an associative sequence with a key-based access, then you should consider <code><a class="el" href="structboost_1_1hana_1_1map.html" title="Basic associative container requiring unique, Comparable and Hashable keys.">hana::map</a></code> or <code><a class="el" href="structboost_1_1hana_1_1set.html" title="Basic unordered container requiring unique, Comparable and Hashable keys.">hana::set</a></code> instead.</p>
<dl class="section note"><dt>Note</dt><dd>When you use a container, remember not to make assumptions about its representation, unless the documentation gives you those guarantees. More details <a class="el" href="index.html#tutorial-containers-types">in the tutorial</a>.</dd></dl>
<h2><a class="anchor" id="autotoc_md388"></a>
Modeled concepts</h2>
<p><code>Sequence</code>, and all the concepts it refines</p>
<h2><a class="anchor" id="autotoc_md389"></a>
Provided operators</h2>
<p>For convenience, the following operators are provided: </p><div class="fragment"><div class="line">xs == ys -&gt; <a class="code" href="group__group-_comparable.html#gacaf1ebea6b3ab96ac9dcb82f0e64e547">equal</a>(xs, ys)</div>
<div class="line">xs != ys -&gt; <a class="code" href="group__group-_comparable.html#gae33be2e0d5e04f19082f4b7740dfc9cd">not_equal</a>(xs, ys)</div>
<div class="line"> </div>
<div class="line">xs &lt; ys -&gt; <a class="code" href="group__group-_orderable.html#gad510011602bdb14686f1c4ec145301c9">less</a>(xs, ys)</div>
<div class="line">xs &lt;= ys -&gt; <a class="code" href="group__group-_orderable.html#ga9917dd82beb67151bf5657245d37b851">less_equal</a>(xs, ys)</div>
<div class="line">xs &gt; ys -&gt; <a class="code" href="group__group-_orderable.html#gaf9a073eafebbe514fb19dff82318f198">greater</a>(xs, ys)</div>
<div class="line">xs &gt;= ys -&gt; <a class="code" href="group__group-_orderable.html#ga6023631e7d0a01e16dc3fa4221fbd703">greater_equal</a>(xs, ys)</div>
<div class="line"> </div>
<div class="line">xs | f -&gt; chain(xs, f)</div>
<div class="line"> </div>
<div class="line">xs[n] -&gt; <a class="code" href="group__group-_iterable.html#ga8a484304380eae38f3d9663d98860129">at</a>(xs, n)</div>
</div><!-- fragment --><h2><a class="anchor" id="autotoc_md390"></a>
Example</h2>
<div class="fragment"><div class="line"><span class="comment">// Copyright Louis Dionne 2013-2017</span></div>
<div class="line"><span class="comment">// Distributed under the Boost Software License, Version 1.0.</span></div>
<div class="line"><span class="comment">// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="assert_8hpp.html">boost/hana/assert.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="equal_8hpp.html">boost/hana/equal.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="integral__constant_8hpp.html">boost/hana/integral_constant.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="transform_8hpp.html">boost/hana/transform.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="tuple_8hpp.html">boost/hana/tuple.hpp</a>&gt;</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;string&gt;</span></div>
<div class="line"><span class="keyword">namespace </span>hana = <a class="code" href="namespaceboost_1_1hana.html">boost::hana</a>;</div>
<div class="line"><span class="keyword">using namespace </span>hana::literals;</div>
<div class="line"> </div>
<div class="line"> </div>
<div class="line"><span class="keyword">struct </span>Fish { std::string name; };</div>
<div class="line"><span class="keyword">struct </span>Cat { std::string name; };</div>
<div class="line"><span class="keyword">struct </span>Dog { std::string name; };</div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> main() {</div>
<div class="line"> hana::tuple&lt;Fish, Cat, Dog&gt; animals{{<span class="stringliteral">&quot;Nemo&quot;</span>}, {<span class="stringliteral">&quot;Garfield&quot;</span>}, {<span class="stringliteral">&quot;Snoopy&quot;</span>}};</div>
<div class="line"> animals[0_c].name = <span class="stringliteral">&quot;Moby Dick&quot;</span>; <span class="comment">// can modify elements in place, like std::tuple</span></div>
<div class="line"> </div>
<div class="line"> <span class="keyword">auto</span> names = hana::transform(animals, [](<span class="keyword">auto</span> a) {</div>
<div class="line"> <span class="keywordflow">return</span> a.name;</div>
<div class="line"> });</div>
<div class="line"> </div>
<div class="line"> <a class="code" href="group__group-assertions.html#ga4796ae107d58b67e0bbccd5ae6f70101">BOOST_HANA_RUNTIME_CHECK</a>(names == hana::make_tuple(<span class="stringliteral">&quot;Moby Dick&quot;</span>, <span class="stringliteral">&quot;Garfield&quot;</span>, <span class="stringliteral">&quot;Snoopy&quot;</span>));</div>
<div class="line">}</div>
</div><!-- fragment --> </div><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="related"></a>
Synopsis of associated functions</h2></td></tr>
<tr class="memitem:ad9d8c7efa77e573eba2dfc48b3343e66"><td class="memItemLeft" align="right" valign="top">template&lt;&gt; </td></tr>
<tr class="memitem:ad9d8c7efa77e573eba2dfc48b3343e66"><td class="memTemplItemLeft" align="right" valign="top">constexpr auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#ad9d8c7efa77e573eba2dfc48b3343e66">make&lt; tuple_tag &gt;</a></td></tr>
<tr class="memdesc:ad9d8c7efa77e573eba2dfc48b3343e66"><td class="mdescLeft">&#160;</td><td class="mdescRight">Function object for creating a <code>tuple</code>. <a href="structboost_1_1hana_1_1tuple.html#ad9d8c7efa77e573eba2dfc48b3343e66">More...</a><br /></td></tr>
<tr class="separator:ad9d8c7efa77e573eba2dfc48b3343e66"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:af3c175cfb83276339f91e867d738a2e6"><td class="memItemLeft" align="right" valign="top"><a id="af3c175cfb83276339f91e867d738a2e6"></a>
constexpr auto&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#af3c175cfb83276339f91e867d738a2e6">make_tuple</a> = <a class="el" href="group__group-core.html#ga1d92480f0af1029878e773dafa3e2f60">make</a>&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html">tuple_tag</a>&gt;</td></tr>
<tr class="memdesc:af3c175cfb83276339f91e867d738a2e6"><td class="mdescLeft">&#160;</td><td class="mdescRight">Alias to <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;</code>; provided for convenience. <br /></td></tr>
<tr class="separator:af3c175cfb83276339f91e867d738a2e6"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a749b564c8f115957837761d75191beac"><td class="memItemLeft" align="right" valign="top"><a id="a749b564c8f115957837761d75191beac"></a>
constexpr auto&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a749b564c8f115957837761d75191beac">to_tuple</a> = <a class="el" href="group__group-core.html#gadc70755c1d059139297814fb3bfeb91e">to</a>&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html">tuple_tag</a>&gt;</td></tr>
<tr class="memdesc:a749b564c8f115957837761d75191beac"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code>to&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;</code>; provided for convenience. <br /></td></tr>
<tr class="separator:a749b564c8f115957837761d75191beac"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a1997546daf58a48cc15498d338a03da3"><td class="memTemplParams" colspan="2">template&lt;typename ... T&gt; </td></tr>
<tr class="memitem:a1997546daf58a48cc15498d338a03da3"><td class="memTemplItemLeft" align="right" valign="top">constexpr implementation_defined&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a1997546daf58a48cc15498d338a03da3">tuple_t</a> {}</td></tr>
<tr class="memdesc:a1997546daf58a48cc15498d338a03da3"><td class="mdescLeft">&#160;</td><td class="mdescRight">Create a tuple specialized for holding <code><a class="el" href="structboost_1_1hana_1_1type.html" title="C++ type in value-level representation.">hana::type</a></code>s. <a href="structboost_1_1hana_1_1tuple.html#a1997546daf58a48cc15498d338a03da3">More...</a><br /></td></tr>
<tr class="separator:a1997546daf58a48cc15498d338a03da3"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a85c2f16caa2a1e12eefd1b3f69fa658e"><td class="memTemplParams" colspan="2">template&lt;typename T , T ... v&gt; </td></tr>
<tr class="memitem:a85c2f16caa2a1e12eefd1b3f69fa658e"><td class="memTemplItemLeft" align="right" valign="top">constexpr implementation_defined&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a85c2f16caa2a1e12eefd1b3f69fa658e">tuple_c</a> {}</td></tr>
<tr class="memdesc:a85c2f16caa2a1e12eefd1b3f69fa658e"><td class="mdescLeft">&#160;</td><td class="mdescRight">Create a tuple specialized for holding <code><a class="el" href="structboost_1_1hana_1_1integral__constant.html" title="Compile-time value of an integral type.">hana::integral_constant</a></code>s. <a href="structboost_1_1hana_1_1tuple.html#a85c2f16caa2a1e12eefd1b3f69fa658e">More...</a><br /></td></tr>
<tr class="separator:a85c2f16caa2a1e12eefd1b3f69fa658e"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="friends"></a>
Friends</h2></td></tr>
<tr class="memitem:a9f7ef8b098a26c3168e1dbd4dd54ff7b"><td class="memTemplParams" colspan="2"><a id="a9f7ef8b098a26c3168e1dbd4dd54ff7b"></a>
template&lt;typename ... T, typename F &gt; </td></tr>
<tr class="memitem:a9f7ef8b098a26c3168e1dbd4dd54ff7b"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a9f7ef8b098a26c3168e1dbd4dd54ff7b">operator|</a> (<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a>&lt; T... &gt;, F)</td></tr>
<tr class="memdesc:a9f7ef8b098a26c3168e1dbd4dd54ff7b"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code>hana::chain</code>. <br /></td></tr>
<tr class="separator:a9f7ef8b098a26c3168e1dbd4dd54ff7b"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a22bef1b2c14cf393a3a9cb1924d8c8ff"><td class="memTemplParams" colspan="2"><a id="a22bef1b2c14cf393a3a9cb1924d8c8ff"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:a22bef1b2c14cf393a3a9cb1924d8c8ff"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a22bef1b2c14cf393a3a9cb1924d8c8ff">operator==</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:a22bef1b2c14cf393a3a9cb1924d8c8ff"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_comparable.html#gacaf1ebea6b3ab96ac9dcb82f0e64e547" title="Returns a Logical representing whether x is equal to y.">hana::equal</a></code> <br /></td></tr>
<tr class="separator:a22bef1b2c14cf393a3a9cb1924d8c8ff"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a4ecea0deb4c00ae2eb0b0713ee0645e9"><td class="memTemplParams" colspan="2"><a id="a4ecea0deb4c00ae2eb0b0713ee0645e9"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:a4ecea0deb4c00ae2eb0b0713ee0645e9"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a4ecea0deb4c00ae2eb0b0713ee0645e9">operator!=</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:a4ecea0deb4c00ae2eb0b0713ee0645e9"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_comparable.html#gae33be2e0d5e04f19082f4b7740dfc9cd" title="Returns a Logical representing whether x is not equal to y.">hana::not_equal</a></code> <br /></td></tr>
<tr class="separator:a4ecea0deb4c00ae2eb0b0713ee0645e9"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:aca31ad50b2d35d48aac88aa762530c75"><td class="memTemplParams" colspan="2"><a id="aca31ad50b2d35d48aac88aa762530c75"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:aca31ad50b2d35d48aac88aa762530c75"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#aca31ad50b2d35d48aac88aa762530c75">operator&lt;</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:aca31ad50b2d35d48aac88aa762530c75"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_orderable.html#gad510011602bdb14686f1c4ec145301c9" title="Returns a Logical representing whether x is less than y.">hana::less</a></code> <br /></td></tr>
<tr class="separator:aca31ad50b2d35d48aac88aa762530c75"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a65b9400772e651101ae83d7f9f7ba84d"><td class="memTemplParams" colspan="2"><a id="a65b9400772e651101ae83d7f9f7ba84d"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:a65b9400772e651101ae83d7f9f7ba84d"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a65b9400772e651101ae83d7f9f7ba84d">operator&gt;</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:a65b9400772e651101ae83d7f9f7ba84d"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_orderable.html#gaf9a073eafebbe514fb19dff82318f198" title="Returns a Logical representing whether x is greater than y.">hana::greater</a></code> <br /></td></tr>
<tr class="separator:a65b9400772e651101ae83d7f9f7ba84d"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a971bac762b767fe0ec222adb367c9aeb"><td class="memTemplParams" colspan="2"><a id="a971bac762b767fe0ec222adb367c9aeb"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:a971bac762b767fe0ec222adb367c9aeb"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a971bac762b767fe0ec222adb367c9aeb">operator&lt;=</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:a971bac762b767fe0ec222adb367c9aeb"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_orderable.html#ga9917dd82beb67151bf5657245d37b851" title="Returns a Logical representing whether x is less than or equal to y.">hana::less_equal</a></code> <br /></td></tr>
<tr class="separator:a971bac762b767fe0ec222adb367c9aeb"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:adec95a8109b858673412671ba341611b"><td class="memTemplParams" colspan="2"><a id="adec95a8109b858673412671ba341611b"></a>
template&lt;typename X , typename Y &gt; </td></tr>
<tr class="memitem:adec95a8109b858673412671ba341611b"><td class="memTemplItemLeft" align="right" valign="top">constexpr friend auto&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#adec95a8109b858673412671ba341611b">operator&gt;=</a> (X &amp;&amp;x, Y &amp;&amp;y)</td></tr>
<tr class="memdesc:adec95a8109b858673412671ba341611b"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_orderable.html#ga6023631e7d0a01e16dc3fa4221fbd703" title="Returns a Logical representing whether x is greater than or equal to y.">hana::greater_equal</a></code> <br /></td></tr>
<tr class="separator:adec95a8109b858673412671ba341611b"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table><table class="memberdecls">
<tr class="heading"><td colspan="2"><h2 class="groupheader"><a name="pub-methods"></a>
Public Member Functions</h2></td></tr>
<tr class="memitem:a8e10223983bfb3873c285be85f7ab273"><td class="memItemLeft" align="right" valign="top"><a id="a8e10223983bfb3873c285be85f7ab273"></a>
constexpr&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a8e10223983bfb3873c285be85f7ab273">tuple</a> ()</td></tr>
<tr class="memdesc:a8e10223983bfb3873c285be85f7ab273"><td class="mdescLeft">&#160;</td><td class="mdescRight">Default constructs the <code>tuple</code>. Only exists when all the elements of the tuple are default constructible. <br /></td></tr>
<tr class="separator:a8e10223983bfb3873c285be85f7ab273"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a4e4e6193df38146b1eab93bcf963fc81"><td class="memItemLeft" align="right" valign="top">constexpr&#160;</td><td class="memItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a4e4e6193df38146b1eab93bcf963fc81">tuple</a> (Xn const &amp;...xn)</td></tr>
<tr class="memdesc:a4e4e6193df38146b1eab93bcf963fc81"><td class="mdescLeft">&#160;</td><td class="mdescRight">Initialize each element of the tuple with the corresponding element from <code>xn...</code>. Only exists when all the elements of the tuple are copy-constructible. <a href="structboost_1_1hana_1_1tuple.html#a4e4e6193df38146b1eab93bcf963fc81">More...</a><br /></td></tr>
<tr class="separator:a4e4e6193df38146b1eab93bcf963fc81"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a9a5dd3930d94a900190de98247e0c415"><td class="memTemplParams" colspan="2">template&lt;typename ... Yn&gt; </td></tr>
<tr class="memitem:a9a5dd3930d94a900190de98247e0c415"><td class="memTemplItemLeft" align="right" valign="top">constexpr&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a9a5dd3930d94a900190de98247e0c415">tuple</a> (Yn &amp;&amp;...yn)</td></tr>
<tr class="memdesc:a9a5dd3930d94a900190de98247e0c415"><td class="mdescLeft">&#160;</td><td class="mdescRight">Initialize each element of the tuple by perfect-forwarding the corresponding element in <code>yn...</code>. Only exists when all the elements of the created tuple are constructible from the corresponding perfect-forwarded value. <a href="structboost_1_1hana_1_1tuple.html#a9a5dd3930d94a900190de98247e0c415">More...</a><br /></td></tr>
<tr class="separator:a9a5dd3930d94a900190de98247e0c415"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a6cf99e86ab1506594eca03881748fe91"><td class="memTemplParams" colspan="2"><a id="a6cf99e86ab1506594eca03881748fe91"></a>
template&lt;typename ... Yn&gt; </td></tr>
<tr class="memitem:a6cf99e86ab1506594eca03881748fe91"><td class="memTemplItemLeft" align="right" valign="top">constexpr&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a6cf99e86ab1506594eca03881748fe91">tuple</a> (<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a>&lt; Yn... &gt; const &amp;other)</td></tr>
<tr class="memdesc:a6cf99e86ab1506594eca03881748fe91"><td class="mdescLeft">&#160;</td><td class="mdescRight">Copy-initialize a tuple from another tuple. Only exists when all the elements of the constructed tuple are copy-constructible from the corresponding element in the source tuple. <br /></td></tr>
<tr class="separator:a6cf99e86ab1506594eca03881748fe91"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ac504757198d85ab9de1258de634e3b71"><td class="memTemplParams" colspan="2"><a id="ac504757198d85ab9de1258de634e3b71"></a>
template&lt;typename ... Yn&gt; </td></tr>
<tr class="memitem:ac504757198d85ab9de1258de634e3b71"><td class="memTemplItemLeft" align="right" valign="top">constexpr&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#ac504757198d85ab9de1258de634e3b71">tuple</a> (<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a>&lt; Yn... &gt; &amp;&amp;other)</td></tr>
<tr class="memdesc:ac504757198d85ab9de1258de634e3b71"><td class="mdescLeft">&#160;</td><td class="mdescRight">Move-initialize a tuple from another tuple. Only exists when all the elements of the constructed tuple are move-constructible from the corresponding element in the source tuple. <br /></td></tr>
<tr class="separator:ac504757198d85ab9de1258de634e3b71"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:acddfa6d631c249ae667d52dd63c0aeaf"><td class="memTemplParams" colspan="2"><a id="acddfa6d631c249ae667d52dd63c0aeaf"></a>
template&lt;typename ... Yn&gt; </td></tr>
<tr class="memitem:acddfa6d631c249ae667d52dd63c0aeaf"><td class="memTemplItemLeft" align="right" valign="top">constexpr <a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a> &amp;&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#acddfa6d631c249ae667d52dd63c0aeaf">operator=</a> (<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a>&lt; Yn... &gt; const &amp;other)</td></tr>
<tr class="memdesc:acddfa6d631c249ae667d52dd63c0aeaf"><td class="mdescLeft">&#160;</td><td class="mdescRight">Assign a tuple to another tuple. Only exists when all the elements of the destination tuple are assignable from the corresponding element in the source tuple. <br /></td></tr>
<tr class="separator:acddfa6d631c249ae667d52dd63c0aeaf"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:ad3f0fe520974a22cc12a978f4b061caa"><td class="memTemplParams" colspan="2"><a id="ad3f0fe520974a22cc12a978f4b061caa"></a>
template&lt;typename ... Yn&gt; </td></tr>
<tr class="memitem:ad3f0fe520974a22cc12a978f4b061caa"><td class="memTemplItemLeft" align="right" valign="top">constexpr <a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a> &amp;&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#ad3f0fe520974a22cc12a978f4b061caa">operator=</a> (<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a>&lt; Yn... &gt; &amp;&amp;other)</td></tr>
<tr class="memdesc:ad3f0fe520974a22cc12a978f4b061caa"><td class="mdescLeft">&#160;</td><td class="mdescRight">Move-assign a tuple to another tuple. Only exists when all the elements of the destination tuple are move-assignable from the corresponding element in the source tuple. <br /></td></tr>
<tr class="separator:ad3f0fe520974a22cc12a978f4b061caa"><td class="memSeparator" colspan="2">&#160;</td></tr>
<tr class="memitem:a8a7edb152340d0eabf67a62f9e25c99f"><td class="memTemplParams" colspan="2"><a id="a8a7edb152340d0eabf67a62f9e25c99f"></a>
template&lt;typename N &gt; </td></tr>
<tr class="memitem:a8a7edb152340d0eabf67a62f9e25c99f"><td class="memTemplItemLeft" align="right" valign="top">constexpr decltype(auto)&#160;</td><td class="memTemplItemRight" valign="bottom"><a class="el" href="structboost_1_1hana_1_1tuple.html#a8a7edb152340d0eabf67a62f9e25c99f">operator[]</a> (N &amp;&amp;n)</td></tr>
<tr class="memdesc:a8a7edb152340d0eabf67a62f9e25c99f"><td class="mdescLeft">&#160;</td><td class="mdescRight">Equivalent to <code><a class="el" href="group__group-_iterable.html#ga8a484304380eae38f3d9663d98860129" title="Returns the nth element of an iterable.">hana::at</a></code> <br /></td></tr>
<tr class="separator:a8a7edb152340d0eabf67a62f9e25c99f"><td class="memSeparator" colspan="2">&#160;</td></tr>
</table>
<h2 class="groupheader">Associated functions</h2>
<a id="ad9d8c7efa77e573eba2dfc48b3343e66"></a>
<h2 class="memtitle"><span class="permalink"><a href="#ad9d8c7efa77e573eba2dfc48b3343e66">&#9670;&nbsp;</a></span>make&lt; tuple_tag &gt;</h2>
<div class="memitem">
<div class="memproto">
<div class="memtemplate">
template&lt;typename ... Xn&gt; </div>
<div class="memtemplate">
template&lt;&gt; </div>
<table class="mlabels">
<tr>
<td class="mlabels-left">
<table class="memname">
<tr>
<td class="memname">constexpr auto <a class="el" href="group__group-core.html#ga1d92480f0af1029878e773dafa3e2f60">make</a>&lt; <a class="el" href="structboost_1_1hana_1_1tuple__tag.html">tuple_tag</a> &gt;</td>
</tr>
</table>
</td>
<td class="mlabels-right">
<span class="mlabels"><span class="mlabel">related</span></span> </td>
</tr>
</table>
</div><div class="memdoc">
<b>Initial value:</b><div class="fragment"><div class="line">= [](<span class="keyword">auto</span>&amp;&amp; ...xs) {</div>
<div class="line"> <span class="keywordflow">return</span> <a class="code" href="structboost_1_1hana_1_1tuple.html#a8e10223983bfb3873c285be85f7ab273">tuple</a>&lt;std::decay_t&lt;decltype(xs)&gt;...&gt;{forwarded(xs)...};</div>
<div class="line"> }</div>
</div><!-- fragment -->
<p>Function object for creating a <code>tuple</code>. </p>
<p>Given zero or more objects <code>xs...</code>, <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;</code> returns a new tuple containing those objects. The elements are held by value inside the resulting tuple, and they are hence copied or moved in. This is analogous to <code>std::make_tuple</code> for creating Hana tuples.</p>
<h2><a class="anchor" id="autotoc_md391"></a>
Example</h2>
<div class="fragment"><div class="line"><span class="comment">// Copyright Louis Dionne 2013-2017</span></div>
<div class="line"><span class="comment">// Distributed under the Boost Software License, Version 1.0.</span></div>
<div class="line"><span class="comment">// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="assert_8hpp.html">boost/hana/assert.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="core_2make_8hpp.html">boost/hana/core/make.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="equal_8hpp.html">boost/hana/equal.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="tuple_8hpp.html">boost/hana/tuple.hpp</a>&gt;</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;string&gt;</span></div>
<div class="line"><span class="keyword">namespace </span>hana = <a class="code" href="namespaceboost_1_1hana.html">boost::hana</a>;</div>
<div class="line"> </div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> main() {</div>
<div class="line"> <span class="keyword">auto</span> xs = hana::make&lt;hana::tuple_tag&gt;(1, 2, <span class="charliteral">&#39;3&#39;</span>, std::string{<span class="stringliteral">&quot;456&quot;</span>});</div>
<div class="line"> </div>
<div class="line"> constexpr <span class="keyword">auto</span> ys = hana::make&lt;hana::tuple_tag&gt;(1, <span class="charliteral">&#39;2&#39;</span>, 3.456);</div>
<div class="line"> static_assert(ys == hana::make_tuple(1, <span class="charliteral">&#39;2&#39;</span>, 3.456), <span class="stringliteral">&quot;&quot;</span>);</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<a id="a1997546daf58a48cc15498d338a03da3"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a1997546daf58a48cc15498d338a03da3">&#9670;&nbsp;</a></span>tuple_t</h2>
<div class="memitem">
<div class="memproto">
<div class="memtemplate">
template&lt;typename ... Xn&gt; </div>
<div class="memtemplate">
template&lt;typename ... T&gt; </div>
<table class="mlabels">
<tr>
<td class="mlabels-left">
<table class="memname">
<tr>
<td class="memname">constexpr implementation_defined tuple_t {}</td>
</tr>
</table>
</td>
<td class="mlabels-right">
<span class="mlabels"><span class="mlabel">related</span></span> </td>
</tr>
</table>
</div><div class="memdoc">
<p>Create a tuple specialized for holding <code><a class="el" href="structboost_1_1hana_1_1type.html" title="C++ type in value-level representation.">hana::type</a></code>s. </p>
<p>This is functionally equivalent to <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;(type_c&lt;T&gt;...)</code>, except that using <code>tuple_t</code> allows the library to perform some compile-time optimizations. Also note that the type of the objects returned by <code>tuple_t</code> and an equivalent call to <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;</code> may differ.</p>
<h2><a class="anchor" id="autotoc_md392"></a>
Example</h2>
<div class="fragment"><div class="line"><span class="comment">// Copyright Louis Dionne 2013-2017</span></div>
<div class="line"><span class="comment">// Distributed under the Boost Software License, Version 1.0.</span></div>
<div class="line"><span class="comment">// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="assert_8hpp.html">boost/hana/assert.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="core_2to_8hpp.html">boost/hana/core/to.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="equal_8hpp.html">boost/hana/equal.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="tuple_8hpp.html">boost/hana/tuple.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="type_8hpp.html">boost/hana/type.hpp</a>&gt;</span></div>
<div class="line"><span class="keyword">namespace </span>hana = <a class="code" href="namespaceboost_1_1hana.html">boost::hana</a>;</div>
<div class="line"> </div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> main() {</div>
<div class="line"> <a class="code" href="group__group-assertions.html#ga2c5006540936d9f8880e3a39f4fcc035">BOOST_HANA_CONSTANT_CHECK</a>(</div>
<div class="line"> hana::to_tuple(hana::tuple_t&lt;<span class="keywordtype">int</span>, <span class="keywordtype">char</span>, <span class="keywordtype">void</span>, <span class="keywordtype">int</span>(<span class="keywordtype">float</span>)&gt;)</div>
<div class="line"> ==</div>
<div class="line"> hana::make_tuple(hana::type_c&lt;int&gt;, hana::type_c&lt;char&gt;, hana::type_c&lt;void&gt;, hana::type_c&lt;<span class="keywordtype">int</span>(<span class="keywordtype">float</span>)&gt;)</div>
<div class="line"> );</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<a id="a85c2f16caa2a1e12eefd1b3f69fa658e"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a85c2f16caa2a1e12eefd1b3f69fa658e">&#9670;&nbsp;</a></span>tuple_c</h2>
<div class="memitem">
<div class="memproto">
<div class="memtemplate">
template&lt;typename ... Xn&gt; </div>
<div class="memtemplate">
template&lt;typename T , T ... v&gt; </div>
<table class="mlabels">
<tr>
<td class="mlabels-left">
<table class="memname">
<tr>
<td class="memname">constexpr implementation_defined tuple_c {}</td>
</tr>
</table>
</td>
<td class="mlabels-right">
<span class="mlabels"><span class="mlabel">related</span></span> </td>
</tr>
</table>
</div><div class="memdoc">
<p>Create a tuple specialized for holding <code><a class="el" href="structboost_1_1hana_1_1integral__constant.html" title="Compile-time value of an integral type.">hana::integral_constant</a></code>s. </p>
<p>This is functionally equivalent to <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;(integral_c&lt;T, v&gt;...)</code>, except that using <code>tuple_c</code> allows the library to perform some compile-time optimizations. Also note that the type of the objects returned by <code>tuple_c</code> and an equivalent call to <code>make&lt;<a class="el" href="structboost_1_1hana_1_1tuple__tag.html" title="Tag representing hana::tuples.">tuple_tag</a>&gt;</code> may differ.</p>
<h2><a class="anchor" id="autotoc_md393"></a>
Example</h2>
<div class="fragment"><div class="line"><span class="comment">// Copyright Louis Dionne 2013-2017</span></div>
<div class="line"><span class="comment">// Distributed under the Boost Software License, Version 1.0.</span></div>
<div class="line"><span class="comment">// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)</span></div>
<div class="line"> </div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="assert_8hpp.html">boost/hana/assert.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="core_2to_8hpp.html">boost/hana/core/to.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="equal_8hpp.html">boost/hana/equal.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="front_8hpp.html">boost/hana/front.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="integral__constant_8hpp.html">boost/hana/integral_constant.hpp</a>&gt;</span></div>
<div class="line"><span class="preprocessor">#include &lt;<a class="code" href="tuple_8hpp.html">boost/hana/tuple.hpp</a>&gt;</span></div>
<div class="line"><span class="keyword">namespace </span>hana = <a class="code" href="namespaceboost_1_1hana.html">boost::hana</a>;</div>
<div class="line"> </div>
<div class="line"> </div>
<div class="line"><span class="keywordtype">int</span> main() {</div>
<div class="line"> <a class="code" href="group__group-assertions.html#ga2c5006540936d9f8880e3a39f4fcc035">BOOST_HANA_CONSTANT_CHECK</a>(</div>
<div class="line"> hana::tuple_c&lt;int, 0, 1, 2&gt;</div>
<div class="line"> ==</div>
<div class="line"> hana::make_tuple(hana::int_c&lt;0&gt;, hana::int_c&lt;1&gt;, hana::int_c&lt;2&gt;)</div>
<div class="line"> );</div>
<div class="line"> </div>
<div class="line"> <a class="code" href="group__group-assertions.html#ga2c5006540936d9f8880e3a39f4fcc035">BOOST_HANA_CONSTANT_CHECK</a>(<a class="code" href="group__group-_iterable.html#ga8a67ea10e8082dbe6705e573fa978444">hana::front</a>(hana::tuple_c&lt;int, 0, 1, 2&gt;) == hana::int_c&lt;0&gt;);</div>
<div class="line">}</div>
</div><!-- fragment -->
</div>
</div>
<h2 class="groupheader">Constructor &amp; Destructor Documentation</h2>
<a id="a4e4e6193df38146b1eab93bcf963fc81"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a4e4e6193df38146b1eab93bcf963fc81">&#9670;&nbsp;</a></span>tuple() <span class="overload">[1/2]</span></h2>
<div class="memitem">
<div class="memproto">
<div class="memtemplate">
template&lt;typename ... Xn&gt; </div>
<table class="mlabels">
<tr>
<td class="mlabels-left">
<table class="memname">
<tr>
<td class="memname">constexpr <a class="el" href="structboost_1_1hana_1_1tuple.html">boost::hana::tuple</a>&lt; Xn &gt;::<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a> </td>
<td>(</td>
<td class="paramtype">Xn const &amp;...&#160;</td>
<td class="paramname"><em>xn</em></td><td>)</td>
<td></td>
</tr>
</table>
</td>
<td class="mlabels-right">
<span class="mlabels"><span class="mlabel">constexpr</span></span> </td>
</tr>
</table>
</div><div class="memdoc">
<p>Initialize each element of the tuple with the corresponding element from <code>xn...</code>. Only exists when all the elements of the tuple are copy-constructible. </p>
<dl class="section note"><dt>Note</dt><dd>Unlike the corresponding constructor for <code><a class="el" href="structstd_1_1tuple.html" title="Adapter for std::tuples.">std::tuple</a></code>, this constructor is not explicit. This allows returning a tuple from a function with the brace-initialization syntax. </dd></dl>
</div>
</div>
<a id="a9a5dd3930d94a900190de98247e0c415"></a>
<h2 class="memtitle"><span class="permalink"><a href="#a9a5dd3930d94a900190de98247e0c415">&#9670;&nbsp;</a></span>tuple() <span class="overload">[2/2]</span></h2>
<div class="memitem">
<div class="memproto">
<div class="memtemplate">
template&lt;typename ... Xn&gt; </div>
<div class="memtemplate">
template&lt;typename ... Yn&gt; </div>
<table class="mlabels">
<tr>
<td class="mlabels-left">
<table class="memname">
<tr>
<td class="memname">constexpr <a class="el" href="structboost_1_1hana_1_1tuple.html">boost::hana::tuple</a>&lt; Xn &gt;::<a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a> </td>
<td>(</td>
<td class="paramtype">Yn &amp;&amp;...&#160;</td>
<td class="paramname"><em>yn</em></td><td>)</td>
<td></td>
</tr>
</table>
</td>
<td class="mlabels-right">
<span class="mlabels"><span class="mlabel">constexpr</span></span> </td>
</tr>
</table>
</div><div class="memdoc">
<p>Initialize each element of the tuple by perfect-forwarding the corresponding element in <code>yn...</code>. Only exists when all the elements of the created tuple are constructible from the corresponding perfect-forwarded value. </p>
<dl class="section note"><dt>Note</dt><dd>Unlike the corresponding constructor for <code><a class="el" href="structstd_1_1tuple.html" title="Adapter for std::tuples.">std::tuple</a></code>, this constructor is not explicit. This allows returning a tuple from a function with the brace-initialization syntax. </dd></dl>
</div>
</div>
</div><!-- contents -->
</div><!-- doc-content -->
<div class="ttc" id="aequal_8hpp_html"><div class="ttname"><a href="equal_8hpp.html">equal.hpp</a></div><div class="ttdoc">Defines boost::hana::equal.</div></div>
<div class="ttc" id="agroup__group-_orderable_html_ga9917dd82beb67151bf5657245d37b851"><div class="ttname"><a href="group__group-_orderable.html#ga9917dd82beb67151bf5657245d37b851">boost::hana::less_equal</a></div><div class="ttdeci">constexpr auto less_equal</div><div class="ttdoc">Returns a Logical representing whether x is less than or equal to y.</div><div class="ttdef"><b>Definition:</b> less_equal.hpp:38</div></div>
<div class="ttc" id="agroup__group-_orderable_html_gad510011602bdb14686f1c4ec145301c9"><div class="ttname"><a href="group__group-_orderable.html#gad510011602bdb14686f1c4ec145301c9">boost::hana::less</a></div><div class="ttdeci">constexpr auto less</div><div class="ttdoc">Returns a Logical representing whether x is less than y.</div><div class="ttdef"><b>Definition:</b> less.hpp:37</div></div>
<div class="ttc" id="agroup__group-assertions_html_ga2c5006540936d9f8880e3a39f4fcc035"><div class="ttname"><a href="group__group-assertions.html#ga2c5006540936d9f8880e3a39f4fcc035">BOOST_HANA_CONSTANT_CHECK</a></div><div class="ttdeci">#define BOOST_HANA_CONSTANT_CHECK(...)</div><div class="ttdoc">Equivalent to BOOST_HANA_CONSTANT_ASSERT, but not influenced by the BOOST_HANA_CONFIG_DISABLE_ASSERTI...</div><div class="ttdef"><b>Definition:</b> assert.hpp:239</div></div>
<div class="ttc" id="atuple_8hpp_html"><div class="ttname"><a href="tuple_8hpp.html">tuple.hpp</a></div><div class="ttdoc">Defines boost::hana::tuple.</div></div>
<div class="ttc" id="aintegral__constant_8hpp_html"><div class="ttname"><a href="integral__constant_8hpp.html">integral_constant.hpp</a></div><div class="ttdoc">Defines boost::hana::integral_constant.</div></div>
<div class="ttc" id="acore_2make_8hpp_html"><div class="ttname"><a href="core_2make_8hpp.html">make.hpp</a></div><div class="ttdoc">Defines boost::hana::make.</div></div>
<div class="ttc" id="agroup__group-_iterable_html_ga8a67ea10e8082dbe6705e573fa978444"><div class="ttname"><a href="group__group-_iterable.html#ga8a67ea10e8082dbe6705e573fa978444">boost::hana::front</a></div><div class="ttdeci">constexpr auto front</div><div class="ttdoc">Returns the first element of a non-empty iterable.</div><div class="ttdef"><b>Definition:</b> front.hpp:32</div></div>
<div class="ttc" id="atype_8hpp_html"><div class="ttname"><a href="type_8hpp.html">type.hpp</a></div><div class="ttdoc">Defines boost::hana::type and related utilities.</div></div>
<div class="ttc" id="anamespaceboost_1_1hana_html"><div class="ttname"><a href="namespaceboost_1_1hana.html">boost::hana</a></div><div class="ttdoc">Namespace containing everything in the library.</div><div class="ttdef"><b>Definition:</b> accessors.hpp:20</div></div>
<div class="ttc" id="aassert_8hpp_html"><div class="ttname"><a href="assert_8hpp.html">assert.hpp</a></div><div class="ttdoc">Defines macros to perform different kinds of assertions.</div></div>
<div class="ttc" id="acore_2to_8hpp_html"><div class="ttname"><a href="core_2to_8hpp.html">to.hpp</a></div><div class="ttdoc">Defines boost::hana::to and related utilities.</div></div>
<div class="ttc" id="astructboost_1_1hana_1_1tuple_html_a8e10223983bfb3873c285be85f7ab273"><div class="ttname"><a href="structboost_1_1hana_1_1tuple.html#a8e10223983bfb3873c285be85f7ab273">boost::hana::tuple::tuple</a></div><div class="ttdeci">constexpr tuple()</div><div class="ttdoc">Default constructs the tuple. Only exists when all the elements of the tuple are default constructibl...</div></div>
<div class="ttc" id="agroup__group-_orderable_html_ga6023631e7d0a01e16dc3fa4221fbd703"><div class="ttname"><a href="group__group-_orderable.html#ga6023631e7d0a01e16dc3fa4221fbd703">boost::hana::greater_equal</a></div><div class="ttdeci">constexpr auto greater_equal</div><div class="ttdoc">Returns a Logical representing whether x is greater than or equal to y.</div><div class="ttdef"><b>Definition:</b> greater_equal.hpp:38</div></div>
<div class="ttc" id="agroup__group-_iterable_html_ga8a484304380eae38f3d9663d98860129"><div class="ttname"><a href="group__group-_iterable.html#ga8a484304380eae38f3d9663d98860129">boost::hana::at</a></div><div class="ttdeci">constexpr auto at</div><div class="ttdoc">Returns the nth element of an iterable.</div><div class="ttdef"><b>Definition:</b> at.hpp:50</div></div>
<div class="ttc" id="atransform_8hpp_html"><div class="ttname"><a href="transform_8hpp.html">transform.hpp</a></div><div class="ttdoc">Defines boost::hana::transform.</div></div>
<div class="ttc" id="agroup__group-assertions_html_ga4796ae107d58b67e0bbccd5ae6f70101"><div class="ttname"><a href="group__group-assertions.html#ga4796ae107d58b67e0bbccd5ae6f70101">BOOST_HANA_RUNTIME_CHECK</a></div><div class="ttdeci">#define BOOST_HANA_RUNTIME_CHECK(...)</div><div class="ttdoc">Equivalent to BOOST_HANA_RUNTIME_ASSERT, but not influenced by the BOOST_HANA_CONFIG_DISABLE_ASSERTIO...</div><div class="ttdef"><b>Definition:</b> assert.hpp:209</div></div>
<div class="ttc" id="afront_8hpp_html"><div class="ttname"><a href="front_8hpp.html">front.hpp</a></div><div class="ttdoc">Defines boost::hana::front.</div></div>
<div class="ttc" id="agroup__group-_comparable_html_gae33be2e0d5e04f19082f4b7740dfc9cd"><div class="ttname"><a href="group__group-_comparable.html#gae33be2e0d5e04f19082f4b7740dfc9cd">boost::hana::not_equal</a></div><div class="ttdeci">constexpr auto not_equal</div><div class="ttdoc">Returns a Logical representing whether x is not equal to y.</div><div class="ttdef"><b>Definition:</b> not_equal.hpp:54</div></div>
<div class="ttc" id="agroup__group-_orderable_html_gaf9a073eafebbe514fb19dff82318f198"><div class="ttname"><a href="group__group-_orderable.html#gaf9a073eafebbe514fb19dff82318f198">boost::hana::greater</a></div><div class="ttdeci">constexpr auto greater</div><div class="ttdoc">Returns a Logical representing whether x is greater than y.</div><div class="ttdef"><b>Definition:</b> greater.hpp:37</div></div>
<div class="ttc" id="agroup__group-_comparable_html_gacaf1ebea6b3ab96ac9dcb82f0e64e547"><div class="ttname"><a href="group__group-_comparable.html#gacaf1ebea6b3ab96ac9dcb82f0e64e547">boost::hana::equal</a></div><div class="ttdeci">constexpr auto equal</div><div class="ttdoc">Returns a Logical representing whether x is equal to y.</div><div class="ttdef"><b>Definition:</b> equal.hpp:64</div></div>
<!--
Copyright Louis Dionne 2013-2017
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
-->
<!-- boost-no-inspect -->
<!-- HTML footer for doxygen 1.8.9.1-->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="navelem"><b>boost</b></li><li class="navelem"><a class="el" href="namespaceboost_1_1hana.html">hana</a></li><li class="navelem"><a class="el" href="structboost_1_1hana_1_1tuple.html">tuple</a></li>
</ul>
</div>
</body>
</html>